IMPACT - Evidence-based depression care
IMPACT research evidence

Evidence for IMPACT

Learn more: Brief bibliography of all IMPACT publications to datelearn more - view the annotated bibliography

As reported in the December 11, 2002 issue of the Journal of the American Medical Association (JAMA), the IMPACT model of depression care more than doubles the effectiveness of depression treatment for older adults in primary care settings.

At 12 months, about half of the patients receiving IMPACT care reported at least a 50 percent reduction in depressive symptoms, compared with only 19 percent of those in usual care. Analysis of data from the survey conducted one year after IMPACT resources were no longer available shows that the benefits of the IMPACT intervention persist after one year. IMPACT patients experienced more than 100 additional depression-free days over a two-year period than those treated in usual care.

Various Settings and Populations

Brief bibliography of adaptationsLearn more: More information about adaptations of IMPACT


Researchers tested the IMPACT model in a variety of settings including HMO, fee-for-service, inner-city county hospital and Veterans Administration clinics. IMPACT was more effective than "usual" care in each of the eight different health care systems. In addition, IMPACT was equally effective with African American, Latino and White patients. It was also more effective than usual care for patients with and without comorbid medical illnesses or anxiety disorders.

Other research studies and evaluations of ongoing programs show that IMPACT is effective with a range of depressed patients:

  • adults of all ages
  • diabetics
  • cancer patients
  • adolescents

Cost Effectiveness

Learn more: abstract describing long-term cost-effectiveness of IMPACT
Learn more: abstract describing cost-effectiveness in diabetics
Learn more: abstract describing program evaluation at Kaiser Permanente

The average cost of the IMPACT program was approximately $580 per participant. This is modest compared to the high annual health care costs (approximately $8,000) in this sample of depressed older adults. The cost of providing IMPACT care as a benefit to an insured population of older adults is less than $1.00 per member per month (PMPM).

When healthcare costs were examined over a four year period, IMPACT patients had lower average costs for all their medical care – about $3,300 less – than patients receiving usual care, even when the cost of IMPACT care is included. This suggests that an initial investment in better depression care not only improves health, it can actually reduce total health care costs over 4 years (1).

Patients with diabetes who received IMPACT care had lower total health care costs than those in usual care, even in a shorter follow-up period (2 years) (2). Lower health care costs in patients who received IMPACT care were also documented by investigators at Kaiser Permanente who tested an adapted version of the program after the original IMPACT trial (3). Read more about Kaiser Permanente's story here.


  1. Unützer J, Katon WJ, Fan MY, Schoenbaum M, Lin EHB, Della Penna R, Powers D. Long-term Cost Effects of Collaborative Care for Late-life Depression. American Journal of Managed Care (in press).
  2. Katon WJ, Unützer J, Fan MY, Williams J, Schoenbaum M, Lin E, Hunkeler E. Cost-effectiveness and Net Benefit of Enhanced Treatment of Depression for Older Adults with Diabetes and Depression. Diabetes Care. 2006; 29(2): 265-270.
  3. Grypma L, Little S, Haverkamp R, Unützer J. Taking an evidence-based model of depression care from research to practice: making lemonade out of depression. General Hospital Psychiatry. 2006; 28: 101-107.

Evidence for Collaborative Depression Care

These findings are consistent with a substantial body of evidence for collaborative care for depression that has emerged over the past 10 years.

A meta-analysis of the evidence for collaborative depression care was published by Gilbody, et al in the Archives of Internal Medicine in 2006. They examined 37 randomized controlled trials with 12,355 total patients. They concluded, “Sufficient randomized evidence had emerged by 2000 to demonstrate the effectiveness of collaborative care beyond conventional levels of statistical significance. Further and subsequent randomized trials have only sought to increase the precision of existing estimates of effectiveness, and it is unlikely that further randomized evidence will overturn this result.”(1)

Learn more: View Institute of Medicine executive summary

An Institute of Medicine (IOM) report, Improving the Quality of Health Care for Mental and Substance-Use Conditions: Quality Chasm Series, was published in 2006. It makes a series of specific recommendations that mirror the IMPACT model of care, including:

  • facilitate the delivery of coordinated care by primary care, mental health and substance-use treatment providers (section 5.2)
  • increase the use of valid and reliable patient questionnaires to assess the progress and outcomes of treatment systematically and reliably (section 4.2)

Similarly, an editorial published in the British Medical Journal in 2006 stated, “The evidence base is now sufficient for the emphasis to shift from research to dissemination and implementation.”(2)

  1. Gilbody S, Bower P, Fletcher J, et al. Collaborative Care for Depression: A Cumulative Meta-analysis and Review of Longer-term Outcomes. Arch Intern Med. 2006;166:2314-2321
  2. Simon G. Collaborative care for depression. BMJ. 2006;332:249-250


Learn more: view brief bibliography of adaptations Learn more: abstract describing the long-term cost-effectiveness of IMPACT Learn more: abstract describing cost-effectiveness in diabetics Learn more: abstract describing program evaluation at Kaiser Permanente Learn more: Abstract of Gilbody article Learn more: brief bibliography of all IMPACT publications to date Learn more: annotated bibliography of all articles published that document the evidence base for IMPACT Learn more: more information about adaptations of IMPACT Learn more: Institute of Medicine executive summary Link to AIMS Center website